Uniform texture for cast in place walls

ABSTRACT

A method of forming a concrete wall having a substantially uniform exterior surface texture. The method includes the initial step of pouring concrete into a wall form. The concrete is poured from a first mixture and is allowed to cure. After the concrete is cured, the wall form is removed from the resultant concrete base structure. A roughened texture is then created on the base structure. A finishing mixture is then applied to the roughened texture. The finishing mixture may be created by separating the aggregate from a portion of the remaining first mixture. The finishing mixture creates a smooth texture on the exterior surfaces of the initially formed base structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation patent application of U.S.patent application Ser. No. 13/595,844 filed oil Aug. 27, 2012, which isa continuation patent application of U.S. patent application Ser. No.12/837,389 filed on Jul. 15, 2010, which is a continuation patentapplication of U.S. patent application Ser. No. 11/724,452 filed on Mar.15, 2007, now U.S. Pat. No. 7,781,019 issued on Aug. 24, 2010, theentire contents of which are incorporated herein by reference.

STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to cast in place concrete wallsand, more particularly, to a method of forming a cast in place concretewall wherein the resultant wall has a substantially smooth and uniformouter surface texture.

2. Description of the Related Art

As is well known in the construction industry, concrete is a commonlyused material for the fabrication of walls and barriers. Thedesirability of the use of concrete as a construction material isattributable to certain characteristics that concrete possesses incomparison to other construction materials. More particularly, walls andbarriers may be quickly and easily constructed through the use ofconcrete, with the concrete also imparting a high level of durability tosuch structures. In addition, the use of concrete for the fabrication ofwalls and barriers offers a high level of design flexibility since theconcrete may be molded into many different shapes and arrangements. Theconcrete is also easily transportable to construction sites via concretetransport trucks.

Many of the concrete walls that are constructed in accordance with thecurrent state of the art are referred to as cast in place walls. Aconcrete cast in place wall is typically constructed on-site rather thanbeing manufactured at an off-site facility and subsequently transportedto the construction site. The fabrication of a cast in place concretewall typically begins with the construction of a concrete wall form.Subsequent to the construction of such form, concrete is pouredthereinto and is given time to cure. Once the concrete has cured, thecorresponding wall form is removed from the fully formed concretestructure. Upon the removal of the form, the exposed walls of theconcrete structure may be sandblasted to apply a finishing texturethereto.

One of the deficiencies associated with the currently known cast inplace wall construction methodology is that the resultant wall or otherstructure tends to have a roughened surface texture upon the removal ofthe form therefrom. In this regard, there tends to be slightinconsistencies in the overall finish of the wall or other structure,such inconsistencies being caused by any one of a number of differentfactors, including inconsistencies in the form work, sandblasting,finishing, concrete and/or the placing or pumping of the concrete intothe form. Further, small holes or other indentations are often foundthroughout the exposed surfaces of the wall or other structure, suchholes or other indentations being formed as a result of the entrapmentof air during the forming process. These holes or other indentations areundesirable, in as much as they diminish the aesthetic appeal of thewall or other structure.

In order to avoid the surface finish inconsistencies highlighted above,there has been developed in the prior art a method of creating uniformtexture concrete walls. In accordance with this methodology, theconcrete wall is “pre cast,” with the cast face of the wall being sidedown and the wall being erected into place through the use of a crane.However, this particular process is not well suited to forming concretestructures wherein multiple faces or sides of the structure are to beprovided with a substantially uniform texture. The present inventionaddresses this need in the art by providing a methodology for formingconcrete structures such as walls or barriers having substantiallysmooth or uniform exterior surface textures.

BRIEF SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, there isprovided a method of forming a cast in place concrete wall having asubstantially uniform exterior surface texture. As indicated above,concrete is a commonly used construction material that comprisesaggregate of various shapes and sizes disposed in cement. The method ofthe present invention includes the initial step of constructing orassembling a concrete wall form in a suitable size and shape, andthereafter pouring a first concrete mixture into the wall form. Theconcrete poured from such first mixture is allowed to partially cureonce poured into the form. Once the concrete is at least partiallycured, the wall form is removed from the resultant base structure.Subsequent to the form removal, the cured concrete structure issubjected to a procedure which creates a roughened surface texture onthe exposed exterior surfaces thereof. Such roughened surface texturemay be formed through the use of a form retarder, a spray on retarder,sand blasting, acid washing, and/or chemical etching.

Subsequent to the roughening of the exposed surfaces of the basestructure, a finishing mixture is then applied to such roughenedsurfaces. In accordance with the present invention, the finishingmixture may be created by separating the aggregate from a portion of theremainder of the first mixture used to initially form the basestructure. However, such finishing mixture may also be formed byseparating the aggregate from a second mixture of the concrete, whereinsuch second mixture is a separate batch of concrete from the firstmixture. The finishing mixture, however derived, is applied to theinitially formed base structure to create a smooth/uniform texture overthe roughened exterior surfaces thereof. As will be recognized, thefully cured finishing mixture ultimately defines the exposed exteriorsurfaces of the concrete structure (e.g., a wall, barrier, etc)comprising the combination of the base structure having the finishingmixture applied thereto.

As is apparent from the foregoing, the present invention provides amethod of constructing a concrete structure such as a cast in place wallhaving substantially more uniform exterior surface textures then thosewhich can be achieved by the formation of cast in place walls usingpresently known techniques. By separating at least the large aggregatefrom the concrete batch used to create the finishing mixture, theapplication of such finishing mixture to the initially formed basestructure is operative to cover any inconsistencies that may otherwisehave been present in such base structure. It is contemplated that thefinishing mixture may be applied through the use of a float which isoperative to work the finishing mixture into any holes or other detentsdisposed in the initially formed base structure. The surface of thefinishing mixture may also be troweled to achieve a harder texture. Theexposed surface of the finishing mixture itself may also be acid washedafter the finishing mixture is allowed to harden to a prescribed level.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdrawings, description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the various embodimentsdisclosed herein will be better understood with respect to the followingdescription and drawings, in which like numbers refer to like partsthroughout, and in which:

FIG. 1 is a perspective view of a cast in place concrete wallconstructed in accordance with techniques known in the prior art;

FIG. 2 is a perspective view of a section of concrete poured into a wallform;

FIG. 3 is a perspective view of a section of the concrete from FIG. 2,wherein the wall form has been removed and a roughened surface has beenapplied to the cured concrete base structure;

FIG. 4 is a perspective view of a section of the concrete base structurefrom FIG. 3, wherein a finishing mixture is being applied to theroughened surface at the base structure; and

FIG. 5 is a perspective view of a concrete wall constructed inaccordance with the method of the present invention.

Common reference numerals are used throughout the drawings and detaileddescription to indicate like elements.

DETAILED DESCRIPTION OF THE INVENTION

The detailed description set forth below is intended as a description ofthe presently preferred embodiment of the invention, and is not intendedto represent the only form in which the present invention may beconstructed or utilized. The description sets forth the functions andsequences of steps for constructing and operating the invention. It isto be understood, however, that the same or equivalent functions andsequences may be accomplished by different embodiments and that they arealso intended to be encompassed within the scope of the invention.

As indicated above, cast in place concrete walls provide numerousadvantages over walls constructed from other building materials. In thisregard, cast in place walls may be quickly and easily constructed, andprovide substantial flexibility in the size and shape of the wall.However, as also indicated above, cast in place walls constructed inaccordance with most prior art fabrication methodologies often includean undesirable rough, non-uniform exterior surface texture. In thisregard, when the concrete is poured into the corresponding wall form,air may become entrapped in small pockets within the concrete. When theconcrete cures and the wall form is removed, these air pockets mayappear as inconsistencies on the exposed surfaces of the resultant wall.These inconsistencies in the wall surface are typically considered to beaesthetically undesirable. FIG. 1 illustrates a cast in place wallconstructed though the use of known, prior art methodologies. As isshown in FIG. 1, small holes or indentations 2 formed as a result ofentrapped air in the concrete poured into wall form used to form thewall are present in various locations on the exposed, exterior surfacesthereof.

The present invention is directed toward creating a cast in place wallhaving a more uniform texture on its surface, thereby increasing itsaesthetic appeal. Referring now to FIGS. 2-5, there is provided a methodof constructing a cast in place concrete wall 10 or other concretestructure having a substantially uniform exterior surface texture.Concrete 12 is a commonly used building material that is comprised ofcement, water, aggregates, and admixtures. Admixtures are materials thatare added to the concrete 12 to give it certain characteristics that itotherwise would not have, such as accelerating or retarding the stettingtime, enhancing frost and sulfate resistance, improving workability, andenhancing finishinability. The aggregates may include sand, pieces ofgravel and stone of various size and shape, and recycled materialsincluding concrete.

According to one embodiment of the present invention, a wall form 14 isinitially constructed in accordance with the desired shape and size ofthe wall or outer structure. In the preferred embodiment of theinvention, the wall form 14 is constructed out of plywood, however,other materials known by those skilled in the art may also be used.After the wall form is constructed, concrete 12 is poured into the wallform 14. In order to enhance the strength of the ultimately formed wallor other structure, re-bar may be placed within the wall form 14 beforethe concrete 12 is poured therein.

Once the concrete 12 is poured into the wall form 14, it is given aprescribed period of time to cure. During the curing process, theconcrete 12 acquires a certain threshold of hardness and strength. Oncethe concrete 12 at least partially cures, the wall form 14 is removed,thereby exposing the exterior surfaces of the base structure (e.g., awall, barrier, etc) formed as a result of the curing of the concrete 12.Thereafter, the exposed surfaces of the base structure formed by thecured concrete 12 are subjected to a procedure which creates a roughenedsurface texture 16 thereon. The roughened surface texture 16 is createdto provide a base for facilitating the adhesion of a finishing mixture18 thereto, as will be described in more detail below. The roughenedsurface texture 16 may be created through the use of a number ofdifferent surface roughening agents or techniques. For example, theroughened surface texture 16 may be achieved through the use of a formretarder or a spray on retarder. A retarder is the substance that slowsthe hydration, or hardening, of the concrete 12. The roughened surfacetexture 16 may alternatively be created by sandblasting, acid watching,or chemically etching the exposed surfaces of the base structure formedby the cured concrete 12. Other techniques known by those of skill inthe art may also use to facilitate the creation of the roughened surfacetexture 16.

Subsequent to the creation of the roughened surface texture upon thebase structure formed by the cured concrete 12, the finishing mixture 18described above is applied thereto. The finishing mixture 18 may becreated by separating large aggregate 20 present in the concrete 12 fromthe remainder thereof. Such large aggregate 20 may include large piecesof gravel or crushed stone found in the original mixture of concrete 12poured into the wall form 14. It is contemplated that by removing thelarge aggregate 20 from the concrete 12, the resultant finishing mixture18 will have a more uniform texture.

In accordance with one embodiment of the present invention, it iscontemplated that the finishing mixture 18 may be created from the samemix or batch of the concrete 12 originally poured into the wall form 14.The use of such original batch may beneficially allow for colorconsistency between the base structure formed from the cured concrete 12and the finishing mixture 18 subsequently applied to the exposedexterior surfaces of such base structure having the roughened surfacetexture 16 formed thereon in the above-described manner. In accordancewith another embodiment of the present invention, the finishing mixture18 may be created from a separate mix of the concrete 12.

As indicated above, the finishing mixture 18 is applied to the roughenedsurface texture 16 of the base structure formed by the cured concrete12, with the cured finishing mixture 18 ultimately defining theuniformly textured exterior surfaces of a final concrete structurecomprising a combination of the base structure and the hardenedfinishing mixture 18. The finishing mixture 18 may be applied to theroughened surface texture 16 through the use of a float. In this regard,the finishing mixture 18 is worked into the roughened surface texture 16until the desired finished surface texture is achieved. At this point,the finishing mixture 18 may be left alone to cure. However, it iscontemplated that the finishing mixture 18 may be troweled before curingto achieve a harder texture. In addition, after the finishing mixture 18fully cures/hardens, it may be acid washed to achieve certain texturedfeatures. An exemplary wall 10 formed in accordance with theaforementioned methodology and possessing the smooth, uniformly texturedexterior surfaces features highlighted above is shown in FIG. 5.However, as also indicated above, the methodology of the presentinvention may also be used to form a plurality of different structuresother than the wall 10 shown in FIG. 5.

The above description is given by way of example, and not limitation.Given the above disclosure, one skilled in the art could devisevariations that are within the scope and spirit of the inventiondisclosed herein. Further, the various features of the embodimentsdisclosed herein can be used alone, or in varying combinations with eachother and are not intended to be limited to the specific combinationdescribed herein. Thus, the scope of the claims is not to be limited bythe illustrated embodiments.

What is claimed is:
 1. A method of forming a concrete structurecomprising the steps of: pouring a first concrete mixture into a form,wherein the first concrete mixture includes large aggregate; allowingthe first concrete mixture to harden and form a concrete base structure;removing the form from the base structure; creating a roughened exteriorsurface on the base structure; creating a finishing mixture byseparating the large aggregate from a portion of the first concretemixture; and applying the finishing mixture to the roughened exteriorsurface of the base structure.
 2. The method of claim 1, wherein theroughened exterior surface is created by applying a form retarder to thebase structure.
 3. The method of claim 1, wherein the roughened exteriorsurface is created by applying a spray on retarder to the basestructure.
 4. The method of claim 1, wherein the roughened surface iscreated by sand blasting the base structure.
 5. The method of claim 1,wherein the roughened surface is created by acid washing the basestructure.
 6. The method of claim 1, wherein the roughened surface iscreated by chemically etching the base structure.
 7. The method of claim1, further comprising the step of troweling the finishing mixture onceapplied to the base structure.
 8. The method of claim 1, furthercomprising the step of allowing the finishing mixture to harden.
 9. Themethod of claim 8, further comprising the step of acid washing thehardened finishing mixture.
 10. A method of forming a concrete structurecomprising the steps of: pouring a first concrete mixture into a form,wherein the first concrete mixture contains large aggregate; allowingthe first concrete mixture to harden and form a concrete base structure;removing the form from the base structure; creating a roughened surfaceon the base structure; creating a finishing mixture by separating largeaggregate from a second mixture of concrete; and applying the finishingmixture to the roughened exterior surface of the base structure.
 11. Themethod of claim 10, wherein the roughened exterior surface is created byapplying a form retarder to the base structure.
 12. The method of claim10, wherein the roughened exterior surface is created by applying aspray on retarder to the base structure.
 13. The method of claim 10,wherein the roughened surface is created by sand blasting the basestructure.
 14. The method of claim 10, wherein the roughened surface iscreated by acid washing the base structure.
 15. The method of claim 10,wherein the roughened surface is created by chemically etching the basestructure.
 16. The method of claim 10, further comprising the step ofallowing the finishing mixture to harden.
 17. The method of claim 16,further comprising the step of acid washing the finishing mixture.
 18. Amethod of forming a concrete structure having a substantially uniformexterior surface texture, comprising the steps of: allowing a firstmixture of concrete including large aggregate to harden and form aconcrete base structure; creating a finishing mixture by separating thelarge aggregate from a portion of the first concrete mixture; andapplying the finishing mixture to the base structure.
 19. The method ofclaim 18 further comprising the step of pouring the first mixture ofconcrete into a wall form.
 20. The method of claim 18 further comprisingthe step of creating a roughened exterior surface on the base structure.